- Terbium-exchanged ZSM-5, MOR and (H)BEA zeolites were silylated with phenyl-, vinyl- and hexadecyl trimethoxysilanes via a post-synthesis grafting. All samples were investigated by means of PXRD, FT-IR, TGA, physical adsorption, DR-UV-Vis and time-resolved photoluminescence spectroscopy. From the comparison of the photoluminescence decays of terbium-exchanged in parent (non-silylated) and silylated zeolites, it resulted that the silylation efficiency of the various alkoxysilanes is determined by the type of zeolite and follows the sequences: phenyl > vinyl > hexadecyl > parent for ZSM-5, hexadecyl a parts per thousand phenyl a parts per thousand vinyl > parent for MOR and hexadecyl > phenyl a parts per thousand vinyl > a parts per thousand parent for BEA zeolites, respectively.